Desktop
/* $Id: smscrypt.c,v 1.3 2010/08/01 13:18:47 khorben Exp $ */
/* Copyright (c) 2010 Pierre Pronchery <khorben@defora.org> */
/* This file is part of DeforaOS Desktop Phone */
/* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 3 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* TODO:
* - set the secret global or per-number
* - apply XOR on the result of the previous buffer
* - XOR against a hash of the secret
* - settings window */
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <System.h>
#include "Phone.h"
/* SMSCrypt */
/* private */
/* types */
typedef struct _SMSCrypt
{
char * secret;
size_t secret_len;
} SMSCrypt;
/* prototypes */
static int _smscrypt_init(PhonePlugin * plugin);
static int _smscrypt_destroy(PhonePlugin * plugin);
static int _smscrypt_event(PhonePlugin * plugin, PhoneEvent event, ...);
static void _smscrypt_settings(PhonePlugin * plugin);
/* public */
/* variables */
PhonePlugin plugin =
{
NULL,
"SMS encryption",
NULL,
_smscrypt_init,
_smscrypt_destroy,
_smscrypt_event,
_smscrypt_settings,
NULL
};
/* private */
/* functions */
/* smscrypt_init */
static int _smscrypt_init(PhonePlugin * plugin)
{
SMSCrypt * smscrypt;
char const * secret;
if((secret = plugin->helper->config_get(plugin->helper->phone,
"smscrypt", "secret")) == NULL)
return 1;
#ifdef DEBUG
fprintf(stderr, "DEBUG: %s() secret=\"%s\"\n", __func__, secret);
#endif
if((smscrypt = malloc(sizeof(*smscrypt))) == NULL)
return error_set_code(1, "%s", strerror(errno));
plugin->priv = smscrypt;
smscrypt->secret = strdup(secret);
smscrypt->secret_len = strlen(secret);
if(smscrypt->secret == NULL || smscrypt->secret_len == 0)
{
_smscrypt_destroy(plugin);
return error_set_code(1, "%s", strerror(errno));
}
return 0;
}
/* smscrypt_destroy */
static int _smscrypt_destroy(PhonePlugin * plugin)
{
SMSCrypt * smscrypt = plugin->priv;
if(smscrypt->secret != NULL)
memset(smscrypt->secret, 0, smscrypt->secret_len);
free(smscrypt->secret);
free(smscrypt);
return 0;
}
/* smscrypt_event */
static void _smscrypt_event_sms_receiving(SMSCrypt * smscrypt,
char const * number, PhoneEncoding * encoding, char ** buf,
size_t * len);
static void _smscrypt_event_sms_sending(SMSCrypt * smscrypt,
char const * number, PhoneEncoding * encoding, char ** buf,
size_t * len);
static int _smscrypt_event(PhonePlugin * plugin, PhoneEvent event, ...)
{
SMSCrypt * smscrypt = plugin->priv;
va_list ap;
char const * number;
PhoneEncoding * encoding;
char ** buf;
size_t * len;
va_start(ap, event);
switch(event)
{
/* our deal */
case PHONE_EVENT_SMS_RECEIVING:
number = va_arg(ap, char const *);
encoding = va_arg(ap, PhoneEncoding *);
buf = va_arg(ap, char **);
len = va_arg(ap, size_t *);
_smscrypt_event_sms_receiving(smscrypt, number,
encoding, buf, len);
break;
case PHONE_EVENT_SMS_SENDING:
number = va_arg(ap, char const *);
encoding = va_arg(ap, PhoneEncoding *);
buf = va_arg(ap, char **);
len = va_arg(ap, size_t *);
_smscrypt_event_sms_sending(smscrypt, number, encoding,
buf, len);
break;
/* ignore the rest */
default:
break;
}
va_end(ap);
return 0;
}
static void _smscrypt_event_sms_receiving(SMSCrypt * smscrypt,
char const * number, PhoneEncoding * encoding, char ** buf,
size_t * len)
{
size_t i;
size_t j = 0;
#ifdef DEBUG
fprintf(stderr, "DEBUG: %s(%u, buf, %lu)\n", __func__, *encoding,
*len);
#endif
if(*encoding != PHONE_ENCODING_DATA)
return; /* not for us */
for(i = 0; i < *len; i++)
{
(*buf)[i] ^= smscrypt->secret[j++];
j %= smscrypt->secret_len;
}
*encoding = PHONE_ENCODING_UTF8;
}
static void _smscrypt_event_sms_sending(SMSCrypt * smscrypt,
char const * number, PhoneEncoding * encoding, char ** buf,
size_t * len)
{
size_t i;
size_t j = 0;
#ifdef DEBUG
fprintf(stderr, "DEBUG: %s(%u, buf, %lu)\n", __func__, *encoding, *len);
#endif
if(*encoding != PHONE_ENCODING_UTF8)
return; /* not for us */
for(i = 0; i < *len; i++)
{
(*buf)[i] ^= smscrypt->secret[j++];
j %= smscrypt->secret_len;
}
*encoding = PHONE_ENCODING_DATA;
}
/* smscrypt_settings */
static void _smscrypt_settings(PhonePlugin * plugin)
{
/* FIXME implement */
}